1. Field
The present disclosure relates to a radio frequency resonator and a magnetic resonance imaging apparatus comprising the same. More particularly, it concerns a radio frequency resonator for a magnetic resonance imaging apparatus capable of effectively increasing an intensity of a magnetic field that is generated by resonating an RF signal and a magnetic resonance imaging apparatus comprising the same.
2. Description of the Related Art
An MRI (magnetic resonance image) method is up-to-date nondestructive, non-radioactive inspection method that is not only effective but comfortable to human body. Currently, it is commonly used in diagnosis of brain, spinal disorder, bone, joint disease, cardiovascular, chest disease, congenital heart disease, myocardial infarction and so forth. The MRI uses such a principle by which when applying a static magnetic field to human body, hydrogen atom nucleus included in cell component molecule has a resonance frequency proportional to the intensity of magnetic field, and thereby electromagnetic waves of the frequency is well absorbed or released.
The MRI apparatus is an apparatus that inspects the inside of human body using such principle. Under a circumstance in which an intense static magnetic field is applied to the portion to be measured, such the MRI apparatus is configured to irradiate a wave corresponding to the resonance frequency to human body in the pulse form and to thereby excite the hydrogen atom nucleus into a high energy state. While the excited hydrogen atom nucleus is returned in a low energy state again, most of the energy held therein is released to outside in the form of magnetic field. The magnetic field released as above is an MR (magnetic resonance) signal.
While the hydrogen atom nucleus releases a magnetic field, when additionally applying a magnetic field having intensity different in accordance with a position, such as a gradient field whose intensity increases in proportional to a distance in one direction from a reference point, the frequency of the magnetic field which is released from the hydrogen atom nucleus at each position has a deviation that is proportional to a position toward a center frequency which is determined by a static magnetic field.
When the MR signal is signal-processed by receiving by means of detector or by receiving antenna, it is therefore possible to obtain am image that shows a density distribution of the hydrogen atom nucleus.
Meanwhile, a Magnetic Resonance Imaging system having a high magnetic field of 7 T (Tesla) or more has an excellent signal-to-noise ratio and resolution, and many researches are now conducted for use as an important tool for clinical diagnosis and analysis in modern medical science. However, in the Magnetic Resonance Imaging system having high magnetic field, it is difficult to obtain an image for clinical diagnosis and analysis because of uniformity of a magnetic field (B1+) that is generated in an RF resonator. Although researches are carried out as well as to a method for overcoming the uniformity problem of magnetic field by use of a multi-channel coil, a satisfactory outcome is not acquired. Specifically, there is no known the RF resonator applicable to a clinical 3 T magnetic resonance imaging system.